Basically the team led by Haotian Wang managed to produce hydrolisis of water into hydrogen with 82% efficiency, four times what was available until recently. It is important that the source is water and not natural gas (for environmental reasons) and that the catalysts are cheap nickel-iron oxides.

There are other details of technical interest that you can read about in the link.

For me this technological revolution implies that the "utopy" of a solar/wind+hydrogen-powered world is already available, that there is no objective reason to continue using fossil sources of energy other than the limits of transition itself (and maybe lesser monetary pretexts, which should be quite negligible in any case).

No more need to rely on expensive and foreign sources of oil, we can produce all energy needed locally with renewables and water. What are we waiting for?